Process of dyeing with sulfur dyes.



. s--- mara r-\ i i Us a Parent @rricyzl MAX BECKE .dTD ALBER'l Bltlli, OF HUCHST-ON-THE-MAIN, GERMANY AS; SIGNORS TO THE FARBWEEKE'VORBL MEISTER, LUCIUS it BRUNING, OF SAME PLACE.

9F DYEiNG WlTl-l SULFUR DYES.

SPECI'i- IUA'lJIOTr-I formingpart of Letters Eatent No. 680,472, dated August 13, 1901.

Application filed May L, 1900. Serial No. 15,532. (llo specimens.)

To all whom it may concern; only incompletely, there being no excess of 56 Be it known that we, MAX BECKE, chemist, reducing agents in the bath. Relying on a citizen of the Empire of Austria-Hungary, these observations, we have found that very and ALBERT BErL, chemist, a citizen of the, good results may be obtained in dyeing with Empire of Germany, both residing at Hochstsulfur dyes by transformiiig them completely on-the-l Iain, Germany, have invented a new into the leuco compounds, dyeing with them and useful Improvement in the Method of in this form, and finally transforming the Dyeing with Sulfur Dyestu ifs in the Vat, of leuco compounds into the dyestulf by oxida which the following is a specification. 'tion by the air or other oxidizing agents-in 1o Sulfur dyestuffs obtained by heating vafact, by dyeing the dyestuffs according to the rious organic substances with sulfur, with or indigo-vat dyeing process. The hydrosuliltewithout sulfids of alkali metals, are now of vat is best suited for reduction, while the copgreat and increasing importance in the dye peras-vat or zinc-vat gives-worse results, to be industry. The process now generally adopted accounted for by the formation of compounds I 5 in dyeing with dyesturfs of this class consists soluble with difficulty of the metallic salts in preparing the bathwith the sulfur dye,

and the leuco compounds of sulfur dyes. The e common salt, sodium carbonate, and a sulfid raw melts are best not employed for reducof an alkali metal, the dyeing taking place tion, but the dye-acids obtained by oxidizing at nearly boiling-point, the material being or acidifying the dissolved raw melts. The so kept as much as possible below the surface preparation of the vat and the dyciugthereiu of the bath. This mode of working, how ever, has great drawbacks and requires scruulous attention, for if the goods be exposed to the air even for a comparatively 2 5 short time unevenness will ensue by the dyestuff separating out on the parts exposed to while cold rinsing will hardly, if at alhrethe air, and thus spots are produced which move them from the fiber. The fturning cannot be removed. The reason why sulfur green of the Shade begins immediately in colors produce uneven and spotted dyes is, an exceedingly even manner on the goods bethe additional excess of lime is generally not required, as when dissolving indigo-white. The leuco compounds possess great affinity for the fiber. They dye rapidly and. evenly,

go-according to our observation, to befound 1n ingtaken out of the bath and rinsed. The

thefollowing: Sodium sulfid, which the dye formation of the dyestuff being completed by stuff either contains when manufactured or exposure to the air the shades maybe transwhich is added to the bath on'dissolving the formed into thorough fast tints bysubsequent dyestuif, has a reducing influence besides a treatment with metallic salts or other oxidiz- 35 dissolving action on the dyestuff'. Besides ing agents, as is done after dyeing in a bath the dissolved'dyestufi the bath contains also containing sulfids of alkali metals. As with the dyestuff reduced to the leuco compound. the indigo-vat, the same material may be in- The dyestuff not reduced and the dyestuff troduced several times, the colors becoming reduced appear to possess different affinities stronger and deeper by giving two or more 40 for the fiber. Therefore they dye the fiber in ends. The remarkable fact here is that the a difierent degree of shade, and as the leuco shades treated with oxidizing agents, such as compound readily oxidizes in contact with sulfate of copper, after the first immersion the oxygen of the air at ordinary temperayield on a second and subsequent immersion ture an opportunity is given by the presdisproportionately stronger and more power- 45 out mode of dyeing for producing unevenfulcolors than when merely exposed totheair.

' ness and spots by the dyestud, separating, The method described is of particular im- 5 out on the material near the boiling-point portance, as the reduction of the sulfur dyes when ezip'osed to air, which on further workmay -be combined with the vat-dyeing of ini n g'in the dye-bath cannot be removed, or digo, it thus being possible to obtain in one are in, general the same as with indi o, onl o.

vat with the recognized fast-sulfur dyes and indigo shades just as fast, yet essentially oheaper,then those obtained with indigo alone and also faster shades than those of indigo, which are topped with other colors. For dyeing in the vet the most suitable are the dyestulfs known as immedial-blue 0, immedial-blaok G and V extra, (Cassella,) Katijen-blue, (Bayer,) Noir Vidal, (St. Denis) Clayton fast-blaok D, and other sulfur (lyestufi...

Example: Four kilos of the dyestuff obiained from para-oxy-para-amido-diphenylamin-o-sulfonie acid are treated with sixty liters of hydrosulfite solution of 13 Baum specific gravity at 50 to 60 centigrade till the color of the solution becomes brown yellow. The leuoo compound thus obtained is then poured into the vet containing about housand liter: )f oolil Water. The mode writing this Vat rend; noon the nature V eeonee of the material to be dyed and is carried out wool-ding as loose material, yarns, stuffs, o s, t me, are employed in a similar manner a rith indigo.

Having now described our invention, What we claim is- The l] erein-desorlbed process of dyeing with sulfur dyestuffs, which consists in transforming the dyestuffs by reduction into leuco compounds, dyeing with them and developing the dyestutl' by oxidation, substantially as set forth.

In testimonylhat we claim the foregoing as our invention we have signed our names in presence of two subscribing witnesses.

MAX BECKE. ALBERT BEIL.

tsitnesses:

HEINRICH HAHN, ALFRED BRTSBOIS. 

